The invention pertains to a method for operation of a public address system with at least one loudspeaker box and with at least one amplifier, which is connected by means of a preferably detachable cable connection and/or by means of a noncable-based connection, to the loudspeaker box.
Public address systems are often set up for the sole purpose of implementing a concert, for example, to provide sound to a concert hall or festival grounds, etc. Since in this case, we are dealing with a mobile system, the loudspeaker box and amplifier are connected to each other by means of a detachable cable connection. Often several amplifiers and several loudspeaker boxes are available, where both the amplifier and the loudspeaker boxes are not identical, but rather are of different models, that is, the single amplifiers have different electrical properties and the loudspeaker boxes have different acoustical, and/or electrical parameters. For this reason it is entirely possible that one and the same amplifier at a first concert, will be working together with type A loudspeaker boxes, and that in an additional, subsequent concert, type B loudspeaker boxes will be connected to said amplifier. Furthermore, it is also possible that at a third concert, both the type A loudspeaker and also the type B loudspeaker will be operating together with the stated amplifier, for example, in a parallel connection. The result of this continually increasing build-up of the public address system is that optimum conditions are not always achieved with regard to a coordination of the amplifier with the loudspeaker boxes, both with regard to electrical circuitry and also with regard to acoustics.
Therefore the invention is based on the problem of specifying a method for operation of a mobile or fixed-site public address system, which always results in a preferred system, in spite of differing combinations of amplifiers and loudspeaker boxes, and without any complicated activities having to be undertaken.
This problem is solved according to this invention, in that in a first process step, the amplifier receives data pertaining to acoustical and/or electrical parameters of the loudspeaker box by inquiry of the loudspeaker box, and that in a second process step, the amplifier is configured automatically, under consideration of the data/parameters, for operation with the connected loudspeaker box. Thus the invention is based on the principle that an automatic configuration will occur, depending on the connected loudspeaker box, that is, due to the automatically occurring ascertainment of parameters, the properties of the public address system are optimized preferably in the electrical and also in the electroacoustical field, in such a manner that the best-possible results can be achieved. The term xe2x80x9camplifierxe2x80x9d in the present case is understood to be a device that allows not only an amplification, but rather also can affect the transient response by means of a signal processing unit.
According to one embodiment of the invention, the configuration is performed with regard to the transient response, in particular with regard to the frequency response and/or phase response. In this regard, the data supplied from the loudspeaker box is evaluated by a controller of the amplifier with regard to an optimized frequency response and subsequently the amplifier will be adjusted by the controller to the parameters of the loudspeaker box in a manner already disclosed to an ordinary technician skilled in the art, so that the desired frequency response will be achieved.
Furthermore, it is an advantage if the configuration is performed with regard to power-handling capacity. Thus, for example, if a loudspeaker box is connected to the amplifier which has only a limited power-handling capacity, that is, if there is a danger, for example, that the very-high-power amplifier might cause damage to or destruction of the loudspeaker box at a corresponding output power, then the configuration can take place in such a manner that operation of the loudspeaker box takes place only up to a limiting power-handling capacity which will preclude any damage.
According to yet another embodiment of the invention, it is possible that the configuration takes place with regard to spatial acousticsxe2x80x94loudspeaker arrangement in the case of several loudspeakers (array formation)xe2x80x94with regard to its use with or without a subwoofer and/or user-specific tone settings.
According to another embodiment of the invention, it is preferable that the configuration takes place under consideration of the changing properties of the loudspeaker box over the course of its aging and/or under consideration of individual properties of the loudspeaker box for example, for tolerance compensation of a single chassis. In this regard, a time-dependent configuration will be produced, that is, upon connection of the loudspeaker box to the amplifier, data will be transmitted along the cable connection which provides information about the age or about the hours of operation already handled by the loudspeaker box. Since the parameters, for example, the sound behavior of the loudspeaker box, change over the course of its aging, then a compensation for this change is possible by means of the configuration. These time-dependent parameters pertain to changes in the acoustical reproduction properties, the electrical properties and/or the magnetic properties. In the case of a configuration as a function of individual properties of the loudspeaker, production control of the individual components of the loudspeaker box can be corrected and thus a consistent quality can be achieved in a simple manner.
According to an aspect of the invention, during the configuration, a check is made to determine whether operation with several loudspeaker boxes is possible/occurring. If this should happen to be the case, then the amplifier receives corresponding data, for example, that two loudspeaker boxes of the same or different type are connected to the amplifier in parallel operation. Now the amplifier will check, based on the data transferred to it, whether this parallel connection of the two boxes is possible, that is, whether an operation can occur without the amplifier itself or the loudspeaker boxes being endangered and whether the operation will lead to satisfactory electrical/electro acoustical results. The same is also true for a series connection of two or more loudspeaker boxes. In this particular case, the amplifier can only be informed by manual input, of whether we are dealing with a parallel or a series connection or with a mixed circuit, for example, the parallel connection of two boxes, for which a third box is wired in series. However, a recognition of this kind can also take place automatically, if for example, an impedance check is performed by the amplifier and at the same time, data is provided that refer to the used loudspeaker boxes. Knowledge of the specifically used loudspeaker boxes, in association with the impedance, will allow the amplifier to decide by itself, whether a parallel or series connection is present.
Furthermore, the invention pertains to a device,for operation of a public address system which has at least one loudspeaker box and one amplifier which is connected by means of a detachable cable connection to the loudspeaker box, and an electrical configuration circuit. The configuration circuit receives data from the loudspeaker box pertaining to its acoustical and/or electrical parameters, said data being supplied preferably by means of the cable connection, and that the configuration circuit automatically configures the public address system , under consideration of the data/parameters, for operation with the connected loudspeaker box. The configuration circuit can be a constituent of the amplifier, that is, a specific assembly of the amplifier, but it is also possible to design this configuration circuit as a separate circuit and to place it in the same housing of the amplifier or in an additional housing. The configuration circuit is in a position to evaluate the data coming from the loudspeaker box and to exert an associated influence, meaning in an electrical regard, on the amplifier and/or on an electronic signal processing unit, which can also be a constituent of the amplifier, but need not be so, and thus the stated optimizing of the public address system is possible.
Furthermore, it is an advantage that the cable connection has a loudspeaker cable and a data cable. In this case, the low-frequency cable is electrically separated from the data cable for driving of the loudspeaker. This does not mean that two separate cables have to be laid, but rather it is entirely possible that the electrical conductors of the loudspeaker cable and data cable are surrounded by a common mantle. But as an alternative, it is also possible that the cable connection is a loudspeaker cable along which the data is also transmitted. In this case, one and the same electrical line can be used for the data transmission and for driving of the loudspeaker. Preferably in the latter case, a time-sharing operation will be carried out, that is, the configuration takes place at a time when no driver data is being transmitted for the loudspeaker and vice-versa. Due to corresponding switching gear, which can be of an electromechanical or also of an electronic nature, this required reverse switching can be implemented, namely from operation of the loudspeaker for acoustic irradiation, to operation for transmission of data or vice-versa.
The data can be transferred along an electrical or optical cable (the latter is called a fiberoptic cable) or by wireless transmission. Suitable for wireless transmission, in particular, is infrared, radio or ultrasonic transmission.
Furthermore, it is an advantage for the loudspeaker box to have an electrical memory unit which supplies the data. The memory unit contains information about the properties of the loudspeaker box, about the type of loudspeaker box, about the serial number of the loudspeaker box, about the hours of operation of the loudspeaker box, about electrotechnical and/or acoustic parameters of the loudspeaker box and/or about possible service instructions on the operation of the loudspeaker box. The above enumeration is not comprehensive, but rather additional data can be saved in the referenced memory. Overall it is thus clear that the memory content pertains to information specific to the loudspeaker and after it is inquired up by the amplifier or rather, by the configuration circuit, it can mean that the configuration can be carried out, that is, that the amplifier is coordinated to the particular, connected loudspeaker box. The amplifier can be designed preferably as a power-handling amplifier. In addition or as an alternative, it is possible that an audio processor is applied to it.
The discussion above and also the discussion below, pertain solely to one channel of the public address system, for example, to the right channel, when a stereo public address system consisting of a right and a left channel is being used. This discussion applies to all channels of the public address system, for example, to the left channel or to additional channels in the case of multichannel systems, such as surround-sound systems or stage monitor systems, for instance. Of course, it is also possible that the memory unit will have information about so-called DSP programs (digital-signal processor programs), whereby the resultant information likewise can be taken into account in the configuration of the amplifier.